400 watt Viper SL, 6 inch flanged inlet & outlet, includes flow auto shut-off switch. Saltwater safe. 400 watt flow rates up to 14,400 GPH. 110/120 volt. When performance matters the Viper Series 400 Watt UV Sterilizer delivers the highest UV outputs and flow rates at a fraction of the size. The Viper Series is designed for maximum performance, power, and reliability. The Viper series replaces multiple lamp units with a single high out put lamp reducing space required for installation. The wider spectrum lamps have approximately 15 to 20 times the germicidal UV intensity of low pressure lamps. The lamps disinfect faster and have greater penetration capability because of the intensity. These lamps disinfect faster and have greater penetration capability because of the intensity. Ultraviolet is a proven dependable and effective method of controlling algae and harmful bacteria without leaving any residuals in the water. Aqua Ultraviolet utilizes the highest quality components designed to work perfectly together maximizing kill rates and insuring ease of installation and maintenance. For ponds: The Viper Unit is Stainless Steel and requires a minimum flow rate of 75 gallons per minute. The Viper 400 watt UV is the premium choice for ponds from 14,400 - 30,000 gallons without plants or shade to eliminate algae or green water. With 50% to 75% plant coverage the Viper 400 Watt UV will handle up to a 50,000 gallon pond. The Viper 400 Watt Sterilizer will clear your water in 3-5 days sometimes overnight and keep it that way. Performance is guaranteed when sized, installed and operated according to our instructions. For Aquariums: The Viper is plastic and requires a minimum flow rate of 75 gallons per minute. The Viper 400 Watt UV is the premium choice for saltwater aquariums up to 3600 gallons. (Fresh water aquariums up to 4800 gallons)